Edit: for more specificity, say in the period from 1600-1800, before any electrical communication but as technology and society were rapidly changing.

I suppose I'm asking this specifically with regard to people in committed, monogamous relationships (as is the norm in western society), but I guess it could really be about anyone. There have always been people who were explorers or had to be away from their families/lovers for sometimes years at a stretch for whatever reason, and being able to communicate in a short period of time--not even instantly--with someone in a different part of your own country, much less part of the world, is relatively new in human history. How did they manage it? How did the loved ones manage it? Was infidelity just rampant for both parties? Or did most people just suffer through it to maintain the societal expectation of fidelity? Did people just abandon relationships for new ones (old-time ghosting)?